反应详情

Dissolve the product of Step 1 (100 mg) and 2-methyl-2-thiopseudourea sulfate (122 mg) in water (0.5 ml) and MeOH (0.5 ml) and heat on a steam bath for 1 hour. If all the starting chloropyrazine is not reacted, add more pseudourea and repeat the procedure. Triturate the resulting residue in EtOH to obtain the sulfate salt of the title compound. Chromatograph the product on a high pressure reversed phase prep C18 column (Dynamax), eluting with MeOH:H2O (40:60), 0.2% TFA, at 10 ml/min., followed by a C18 Magnum 20 column (Whatman), eluting with MeOH:H2O (30:70), 0.2% TFA. Dissolve the resultant residue in 1N HCl, evaporate the solvent, redissolve in water and lyophilize to obtain the title compound as a yellow solid, m.p. 100° (d), M+ =272.

1. temperatureheat on a steam bath for 1 hour
2. customTriturate the resulting residue in EtOH